* {
    padding: 0;
    margin: 0;
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    height: 100vh;
    background: #000;
}

.glowing {
    position: relative;
    min-width: 750px;
    height: 750px;
    margin: -150px;
    animation: changeColor 10s linear infinite;
    transform-origin: right;
}

.glowing:nth-child(even) {
    transform-origin: left;
}

@keyframes changeColor {
    0% {
        filter: hue-rotate(0deg);
        transform: rotate(0deg);
    }
    100% {
        filter: hue-rotate(360deg);
        transform: rotate(360deg);
    }
}

.glowing span {
    position: absolute;
    top: calc(80px * var(--i));
    left: calc(80px * var(--i));
    right: calc(80px * var(--i));
    bottom: calc(80px * var(--i));
    /* background: red; */
}

.glowing span::before {
    content: "";
    position: absolute;
    top: 50%;
    left: -8px;
    width: 15px;
    height: 15px;
    border-radius: 50%;
    background: #f00;
}

.glowing span:nth-child(3n + 1):before {
    background: rgba(134, 255, 0, 1);
    box-shadow: 0 0 20px rgba(134, 255, 0, 1), 0 0 40px rgba(134, 255, 0, 1), 0 0 60px rgba(134, 255, 0, 1), 0 0 80px rgba(134, 255, 0, 1), 0 0 80px rgba(134, 255, 0, 0.1);
}

.glowing span:nth-child(3n + 2):before {
    background: rgba(255, 214, 0, 1);
    box-shadow: 0 0 20px rgba(255, 214, 0, 1), 0 0 40px rgba(255, 214, 0, 1), 0 0 60px rgba(255, 214, 0, 1), 0 0 80px rgba(255, 214, 0, 1), 0 0 80px rgba(255, 214, 0, .1);
}

.glowing span:nth-child(3n + 3):before {
    background: rgba(0, 226, 255, 1);
    box-shadow: 0 0 20px rgba(0, 226, 255, 1), 0 0 40px rgba(0, 226, 255, 1), 0 0 60px rgba(0, 226, 255, 1), 0 0 80px rgba(0, 226, 255, 1), 0 0 80px rgba(0, 226, 255, 0.1);
}

.glowing span:nth-child(3n + 1) {
    animation: animate 10s alternate infinite;
}

.glowing span:nth-child(3n + 2) {
    animation: animate-reverse 10s alternate infinite;
}

.glowing span:nth-child(3n + 3) {
    animation: animate 8s alternate infinite;
}

@keyframes animate {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}

@keyframes animate-reverse {
    0% {
        transform: rotate(360deg);
    }
    100% {
        transform: rotate(0deg);
    }
}